BirdAnalyst
Guild · Connecticut · BBS 2026 Release · 1966–2025

Wetland Birds In Connecticut

All statesConnecticut

10 species in this guild. As a group they are -90%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Wetland birds as a group have collapsed in Connecticut, down 90% since 1968.

Wetland Birds In Connecticut Population Forecast

If the recent trend holds, Wetland birds in Connecticut is projected to fall about 100% by 2030 — from 5.6 in 2025 to a central estimate of 0.00 (95% range 0.00–19). A 5-year backtest shows a typical error of ±155.3%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2030TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.00Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1995% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±155.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Wetland birds in Connecticut is projected to fall about 100% by 2030 — from 5.6 in 2025 to a central estimate of 0.00 (95% range 0.00–19). A 5-year backtest shows a typical error of ±155.3%, with 100% of held-out values landing inside the 95% band.19662030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20260.000.0019
20270.000.0019
20280.000.0019
20290.000.0019
20300.000.0019

Member Species In Connecticut

Wetland birds species in Connecticut.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
Double-crested CormorantPhalacrocoracidae-72%
Red-winged BlackbirdIcteridae-72%
Belted KingfisherAlcedinidae-53%
Green HeronArdeidae-46%
Ring-billed GullLaridae-19%
Herring GullLaridae-5%
Black-crowned Night HeronArdeidae-5%
Great Black-backed GullLaridae+7%
Swamp SparrowPasserellidae+9%
Great Blue HeronArdeidae+668%

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.